PG1553+113 Analysis with lstchain v0.9.13 E. Pons

General information

Name of the source: PG 1553+113
Brief description of the source:
- Object type : AGN
- Redshift (z) : 0.433 Dorigo Jones et al
- BL Lac
- RA: 15 5543.044 (hh mm ss), Dec: +11 11 24.365 (dd mm ss)
- RA, Dec in deg (ICRS): 238.92934976, 11.19010155

Analysis by Estelle Pons (LAPP - estelle.pons@lapp.in2p3.fr)

Dataset (< 2022-05-24)

Number of selected observations : 39
Runs: 4333 - 8425
Date range: 2021-04-08 to 2022-05-23

obsids:

[4333 4334 4335 4336 4343 4344 4363 4364 4365 4366 4367 4368 4514 4515
4652 4653 4654 4902 4903 4904 4905 4930 4940 4941 4942 4943 7153 7154
8059 8060 8061 8062 8063 8064 8377 8378 8379 8424 8425]

DL1 data

DL1 files produced by LSTOSA (lstchain v0.9)

original real DL1a data

/fefs/aswg/data/real/DL1/{Date}/v0.9/tailcut84/

DL1 to DL2

Random Forest

Standard ‘un-tuned’ production for processing standard AGN data, with lstchain v0.9.12 standard settings (az instead of sin(az) in training features). Reprocessed with v0.9.13 for faulty dec_931:

/fefs/aswg/data/models/AllSky/20230414_v0.9.13_dec_931_az_tel/dec_931

DL2 data

/fefs/aswg/workspace/estelle.pons/PG1553/DL2/{Date}/v0.9.13/tailcut84

NB: The lstchain config file from the RF production is specified for lstchain_dl1_to_dl2

Example:

lstchain_dl1_to_dl2 
  -f /fefs/aswg/data/real//DL1/20220617/v0.9/tailcut84/dl1_LST-1.Run08787.0019.h5                 
  --output-dir /fefs/aswg/workspace/estelle.pons/PG1553//DL2/20220617/v0.9.13/tailcut84/                 
  --path-models /fefs/aswg/data/models/AllSky/20230414_v0.9.13_dec_931_az_tel/dec_931/ 
  --config /fefs/aswg/data/models/AllSky/20230414_v0.9.13_dec_931_az_tel/dec_931/lstchain_config.json

DL2 to DL3

DL3 cuts: source-independent analysis & global cuts:
- gh_cut = 0.7
- theta_cut = 0.2

MC DL2 files used to produce IRF

/fefs/aswg/data/mc/DL2/AllSky/20230414_v0.9.13_dec_931_az_tel/TestingDataset/dec_931

The closest node compared to the telescope pointing position is then selected for each run to create the corresponding IRF.

Example:

lstchain_create_irf_files  
  -g /fefs/aswg/data/mc/DL2/AllSky/20230414_v0.9.13_dec_931_az_tel/TestingDataset/dec_931/node_theta_32.059_az_248.099_/dl2_20230414_v0.9.13_dec_931_az_tel_node_theta_32.059_az_248.099__merged.h5                 
  -o /fefs/aswg/workspace/estelle.pons/PG1553/IRF/allsky/irf_20230414_v0.9.13_dec_931_az_tel_dec_931_node_theta_32.059_az_248.099_ghcut0.7_run8787.fits.gz
  --point-like  --global-theta-cut 0.2 --global-gh-cut 0.7

DL3 data

/fefs/aswg/workspace/estelle.pons/PG1553/DL3/lstchain/v0.9.13/point_like/offset0.4/ghcut0.7/{Date}

Example:

lstchain_create_dl3_file 
  -d /fefs/aswg/workspace/estelle.pons/PG1553//DL2/20220617/v0.9.13/tailcut84/dl2_LST-1.Run08787.h5     
  -o /fefs/aswg/workspace/estelle.pons/PG1553/DL3/lstchain/v0.9.13/point_like/offset0.4/ghcut0.7/20220617     
  --input-irf /fefs/aswg/workspace/estelle.pons/PG1553//IRF/allsky/irf_20230414_v0.9.13_dec_931_az_tel_dec_931_node_theta_32.059_az_248.099_ghcut0.7_run8787.fits.gz     
  --source-name PG1553+113     --source-ra " 238.92935002022deg"     --source-dec " 11.19010156943deg"  
  --global-gh-cut 0.7 --gzip

gammapy analysis parameters

gammapy version v1.0.1
DL4 datasets
- on_radius = 0.2 deg / exclusion_radius = 0.35 deg
- Reflected Regions Background method
  - multiple off regions (used the default ReflectedRegionsFinder)
- Safe Energy mask:
  - MapDataset: methods=["offset-max"], offset_max=4 deg
  - SpectrumDataset: NO safe mask
- Energy axes:
  - True: 10 GeV to 10 TeV with 5 bins per decade
  - Reco: 10 GeV to 40 TeV with 10 bins per decade
DL5 datasets
- Spectral analysis
  - Joint fit
  - Energy axes Flux Points: 10 GeV to 10 TeV with 5 bins per decade
  - Reference energy: pivot energy from a power-law fit = 0.12 TeV
  - SED fitting: best fit between power-law + EBL (Dominguez), log-parabol + EBL, exponantial cutoff power-law + EBL

Analysis Results

Livetime : 9.92 h

Significance : 16.13 sigma

Excess : 5957.2

S/B : 0.057

Rate : 10.00 per min

Fluxes (for spectral model PL+EBL)

Energy flux (0.01 TeV-10.0 TeV) = 1.748e-10 pm 3.206e-11 TeV / (cm2 s)
Integral flux (0.01 TeV-10.0 TeV) = 7.909e-09 pm 1.886e-09 1 / (cm2 s)
Integral flux (100 GeV-10.0 TeV) = 1.221e-10 pm 8.873e-12 1 / (cm2 s)